Oreo/MiHec 10mm Review

[seaboltm]

I received my Oreo/MiHec 10mm mold this summer. It was the group buy with 3 pin sets. 4 cavity brass mold. Texas is hot, plus I moved this summer, so I just got around to using the mold today.

First, I have only been casting for a couple of years. I started with a Lyman pot and ladle and used Lee molds. I had some success, and some failures. I then upgraded to a Lee ProMelt 20. So for this pour session I did several things different:

1. I did more mold prep. I used brake cleaner and thoroughly degreased the mold. I then carefully lubed the pins and sprue plate.
2. I bought a hot plate to pre-heat the mold. Wal-Mart, $10. Money well spent.
3. I bought a thermometer. More on that in a moment.

I fired up the furnace and got it to the temperature I normally cast at, except this time I used a thermometer: 900 degrees! No wonder I tore up several sets of Lee molds. I backed the temperature to 800 degrees and did pour one. As I expected, even using the hot plate my first pour had bad fill out. By the time I had filled the mold three times, I was rewarded with near perfect boolits! I got perfect pours after that until the last pour. I decided to experiment with temperature in the middle of the session. Things started to get sluggish at 750 degrees. Boolits were OK. I discovered that this setup worked good at 775 to 800 degrees. Maybe I am just too slow. But for my pace and the huge brass mold, that was the temperature that worked.

Results: with the flat nose pins installed I got 226 grain boolits measuring .402.

Very impressed with the mold and pleased with the results.

Forgot to mention, alloy was WW, or at least thats what I was told it was.

[dragon813gt]

I have some loaded up but haven't had time to get to the range. My results w/ 96/2/2 alloy yielded .403 bullets. Large HP 219 grains, Cup HP 224 grains and Solid 229 grains. I was able to cast well w/ a 725 degree pot temp. I've found most of his molds work well at this temp. Hopefully I can get out and shoot them tomorrow.

[Elkins45]

I was able to cast well w/ a 725 degree pot temp. I've found most of his molds work well at this temp.

That's interesting, and not my experience at all. My 4 cavity ones need to run at 840 to get good drop off of the pins, and they aren't frosty at that temp.

[dragon813gt]

Wish I knew what my mold temp was and you knew what yours was. 840 is really excessive. My alloy has tin in it and I cringe if I have to take it to 750.

[Hamish]

That's interesting, and not my experience at all. My 4 cavity ones need to run at 840 to get good drop off of the pins, and they aren't frosty at that temp.

Apologies for the thread drift, but this sounds exactly like a shortage of tin in the alloy.

[Elkins45]

Apologies for the thread drift, but this sounds exactly like a shortage of tin in the alloy.

That's quite possible. The last time I cast with my 45-185 SWC HP I used one of those big fat isotope containers as my lead source.

I think maybe I need to polish my pins?

[dragon813gt]

There isn't a lack of tin in the isotope cores. The big ones have one percent. They are all I used for years.